This project is designed to investigate mechanisms involved in development of granulomatosus hypersensitivity (GHR) immunologically, pathologically and biochemically. In addition chemical and physical factors which control development of GHR are also studied. As an experimental model we use GHR induced by metal (Beryllium oxide) in man, as well as tissue cultured circulating monocytes and other cells from individuals with GHR. Isolation and characterization of substances involved in transformation of precursor cells to organized epitheliod cells will be attempted.